<template>
    <div>

        <!-- 顶部滑动条 -->
        <div id="slider" class="mui-slider">
            <div id="sliderSegmentedControl" class="mui-scroll-wrapper mui-slider-indicator mui-segmented-control mui-segmented-control-inverted">
                <div class="mui-scroll">
                    <a :class="['mui-control-item', item.id==0 ? 'mui-active' : '']" v-for="item in cates" :key="item.id" @tap="getPhotoListByCateId(item.id)">
                        {{ item.title }}
                    </a>
                </div>
            </div>
        </div>

        <!-- 图片列表区域 -->
        <ul class="photo-list">
            <router-link  v-for="item in list" :key="item.id" :to="'/home/photoinfo/' + item.id" tag="li">
                <img v-lazy="item.img_url">
                <div class="info">
                    <h1 class="info-title">{{ item.title }}</h1>
                    <div class="info-body">{{ item.zhaiyao }}</div>
                </div>
            </router-link>
        </ul>

    </div>
</template>

<script>
//1. 导入mui的JS文件
import mui from '../../lib/mui/js/mui.min.js';

export default{
    data() {
        return {
            cates : [],     //所有分类的列表数组
            list : []
        };
    },
    created() {
        this.getAllCategory();
        //默认进入页面，就主动请求所有图片列表的数据 
        this.getPhotoListByCateId(0);
    },
    mounted() { 
        //当 组件中的DOM结果被渲染好并放到页面中后，会执行这个钩子函数
        //如果操作元素了，最好在mounted里面，因为，这个时候的DOM元素，是最新的
        //2. 初始化滑动控件
        mui('.mui-scroll-wrapper').scroll({
            deceleration: 0.0005 //flick 减速系数，系数越大，滚动速度越慢，滚动距离越小，默认值0.0006
        });
    },
    methods : {
        getAllCategory() {
         //获取所有的图片分类
         this.$http.get('api/getimgcategory').then(result=>{
             if(result.body.status === 0){
                 //手动拼接出一个最完整的分类列表
                 result.body.message.unshift({title:'全部',id:0});
                 this.cates = result.body.message;
             }
         })
        },
        getPhotoListByCateId(cateId) {
            //根据 分类id，获取图片列表
            this.$http.get('api/getimages/' + cateId).then(result =>{
               if(result.body.status ===0){
                   this.list = result.body.message;
               }
            })
        }
    }
};
</script>

<style lang="scss" scoped>
*{
    touch-action: pan-y;
}
.photo-list {
    list-style: none;
    margin: 0;
    padding: 10px;
    padding-bottom: 0;
    li {
        background-color:#ccc;
        text-align: center;
        margin-bottom: 10px;
        box-shadow: 0 0 9px #999;
        position: relative;
        img{
            width: 100%;
            vertical-align: middle;
        }
        image[lazy=loading] {
        width: 40px;
        height: 300px;
        margin: auto;
        }

        .info{
            color:white;
            text-align: left;
            position: absolute;
            bottom:0;
            background-color:rgba(0,0,0,0.4);
            max-height: 84px;
            .info-title{
                font-size: 14px;
            }
            .info-body{
                font-size: 13px;
            }
        }
    }
}

</style>